Machine for producing moulds consisting of identical mould parts

ABSTRACT

In a continuous casting system, a machine for producing foundry moulds consisting of identical mould parts which after having been produced from foundry sand or similar material that is compressed by means of a pattern board, are pushed out onto a guideway and added to previously produced moulds, said guideway being equipped with reciprocating mould advancing means, the positive or mould advancing movement of which is coordinated with that of the pattern board.

I Umted States Patent 1 1111 3,744,552 Lundsgart 5] July 10, 1973 [54] MACHINE FOR PRODUCING MOULDS 3,303,535 2/1967 Rearwin et a1 164/213 CONSISTING 0 IDENTICAL MOULD 3,556,196 1/1971 Buhler 164/187 PARTS 3,008,199 11/1961 Jeppesen 164/78 X [75] Inventor: Henning Borge Lundsgart, EIGN PATENTS OR APPLICATIONS Karlslunde, Denmark 1,066,833 4/1967 Great Britain 164/ 180 [73] Assignee: Dansk Industri Syndikat A/S,

Herlev, Denmark Primary Examiner--J. Spencer Overholser Assistant ExamirierV. K. Rising [22] Flled' 1970 Attorney-lmirie and Smiley [21] Appl. No.: 60,829

57 ABSTRACT [30] Foreign Application Priority Data 1 Aug 28 1969 Denmaxk 4621/69 In a continuous casting system, a machine for producing foundry moulds consisting of identical mould parts [52] Us. CL 164/187 164/213 164/401 which after having been produced from foundry sand 51 Int. Cl. 1152c 17/00 Similar material that is c"mlmsel by means a 58 Field of Search 164/344, 213, 182, Patter" are Pushed a gufidewly and 164/187 188 181 180 401 403 78 227 added to prev1ous1y produced moulds, sald gu1deway being equipped with reciprocating mould advancing means, the positive or mould advancing movement of [56] g sgg gg which is coordinated with that of the pattern board.

704,951 7/1902 Adams 164/188 4 Claims, 2 Drawing Figures MACHINE FOR PRODUCING MOULDS CONSISTING OF IDENTICAL MOULD PARTS BACKGROUND OF THE INVENTION In a continuous casting system such as disclosed in US. Pat. No. 3,008,199, a mould part is formed of sand or other particulate material in a mould chamber for the successive production of identical mould parts between a pair of opposed pattern boards, of which one serves to push the finished mould part out on to a substantially horizontal guideway where the mould parts are aligned in abutment and advanced intermittently concurrently with the mould part production. A pouring station above the guideway is operated intermittently in synchronism with the intermittent advance of the mould parts to pour fluid casting material into a newly positioned casting cavity. The guideway extends beyond the pouring station a distance to enable the casting material to solidify sufficiently to be undamaged by a fall from the end of the guideway which causes breaking or crumbling of the mould parts and freeing of the castings.

In apparatus of this kind, it is possible for the production of a mould part and its subsequent lining up with previously produced mould parts, to take place with great accuracy, and in order that this accuracy will not be lost prior to the pouring which is effected while the mould is on the guideway, this guideway must be of a very stable type. In practice, a guideway is used which consists of a rigid bed on which the mould is intermittently advanced while overcoming frictional resistance. This frictional resistance possibly will have to be increased, such as by weight-loading the mould parts, in order to become sufficiently high so as to keep the mould parts together until the pouring has taken place and the castings are sufficiently hardened.

Inexisting machines of the kind stated, the length of the guideway, as a rule, amounts to from 4 to 6 meters depending, among other things, on the hardening time and, therefore, on the weight of the castings produced. In such machines, the pressure exerted by the displaceable pattern board is sufficient to produce the intermittent or stepwise advance of the mould, provided that the foundry sand is of such a quality as to stand up to the pressure.

When the size of the castings is increased, the frictional resistance grows rapidly, not only on account of the increased weight of the cast material but, above all, due to theincreased period of hardening which calls for a corresponding extension of the guideway. When the resistance to the stepwise advance of the mould, on account of these causes, exceeds a certain limit, the pres sure from the displaceable pattern board no longer will be able to cope with the advance in the prescribed manner, either because the pressure in itself is too low, or becausethe material of the mould parts is unable to stand up to the necessary surface pressure. It would be conceivable to compensate for this by lowering the frictioncoefficient betweenthe guideway and the mould parts, but hereby the risk arises of the individual mould parts not holding together sufficiently securely, so that the castings produced become inaccurate.

Summary of The Invention In apparatus according to the invention, the difficulties connected with the stepwise advance of the mould parts are solved by the guideway being equipped with reciprocating mould parts advancing means which are arranged to be brought into and out of engagement with the outside of the aligned mould parts and, in the engaged position, to be displaced at the same speed as that of the pattern board.

In this case, the displaceable pattern board is partly or completely relieved of the task of advancing the abutting mould parts and, at the same time, it is possible to maintain the surface pressure between these mould parts at a suitably low magnitude since at any rate a significant part of the force required for the advancing is transmitted to the outer surfaces of the mould parts.

It is, of course, important that movement of the mould part advancing means in the direction of displacement is accurately coordinated with the displacement of the pattern board, by means of which a mould part that has just been produced is joined to the mould part previously just formed. Otherwise, the necessary unity and cooperation of the mould parts could be lost. According to the invention, the difficulties in this respect can expediently be overcome by the mould part advancing means being arranged, during the normal operation of the machine, to act upon the mould parts with a displacement force which, in itself, is inadequate for overcoming the displacement resistance of the mould on the guideway. The necessary supplementary displacement force must then be supplied by the displaceable pattern board via the mould part or parts last produced, which makes it quite certain that the mould part advancing means will function in the manner intended. These means may, for instance, be adjusted to furnish -90 percent of the displacement force required. In practice, the mould part advancing means should also by themselves be capable of providing the full displacement force on the mouldparts, e.g., with a view to clearing the guideway when the casting process is interrupted. It is possible, moreover, in the dimensioning of the mould part advancing means, to pay regard to the fact that the resistance against the displacement of the mould parts on the guideway may be significantly increased when the normal operation is temporarily interrupted.

According to the invention, it is preferred that the mould part advancing means comprise two rails located atopposite sides of the guideway and parallel thereto, which rails are supported by the guideway so as to be longitudinally displaceable, and are connected to a common reciprocating mechanism, at least one of the rails being transversely movable towards and away from the mould parts standing on the guideway. The transversal movement should only be very slight, by way of example, of the order of one or some few tenths ofa millimeter, as the transversal movement should rather render pressure relief between the mouldparts and the rail, than an actual separation between these parts. Thus, during the return movement of the rails relative to the mould parts, foreign bodies should not be able to penetrate between the. mould parts and the rails, since such foreign bodies could cause a transverse displacement between the mould parts and a thereby resulting inaccuracy in the castings produced.

BRIEF DESCRIPTION OF DRAWING FIG: 1 is a side view in elevation of the most important details of the machine according to the invention, and

FIG. 2 an enlarged view in cross section essentially along line II-ll in FIG. 1.

In the drawings, a mould part producing apparatus 1, which may be of a known type, comprises a moulding chamber 2, in which the mould parts are produced successively between a pair of opposed pattern boards, of which only the left or rearmost board 3 is shown, the pattem boards forming casting surfaces on the ends of the mould parts. After a mould part has been produced, this pattern board 3 is displaceable in the forward direction through the moulding chamber 2 in order to push the mould part 4 out on to a guideway 5, where it is added to the mould formed by the previously produced mould parts 6, the casting surfaces on the abutting ends of adjoining mould parts jointly forming an open top casting cavity.

In the embodiment shown, the guideway 5 consists of a rigid bed having an accurately machined surface, on which the mould parts 6 are to be displaced in the direction of the arrow 7 shown in FIG. 1. The guideway or bed 5 rests on suitable foundations 8. As the mould parts are displaced along the guideway the jointly formed casting cavities pass beneath and are filled with liquid casting material at a pouring station.

Along the sides of the bed 5, a pair of rails 9 are provided which, in the embodiment shown, are constituted by channel irons, whose bottom sides facing the mould parts 6 may be ground, machined or otherwise finished with the necessary precision so that it is possible for them to be brought into firm surface contact against the sides of the mould parts. The channel rails are supported by rollers 10 carried by the bed 5 and permitting the rails to be displaced in their longitudinal direction.

As appears most clearly from FIG. 2, the lateral channel rails 9 are connected to each other via yokelike frames 11 which, in the embodiment shown, are constructed of T-irons and comprise a bottom piece 12 which extends in the transverse direction below the bed 5, and two upstanding legs 13 each of which is connected to one of the two lateral rails 9. As far as the left-hand rail is concerned, this connection, in FIG. 2, is assumed to be of a firm, although adjustable type, while between the right-hand lateral rail 9 and each of the corresponding legs 13, a fluid pressure operated jack is inserted comprising a cylinder 14 mounted firmly on the rail and an associated piston 15 which is carried by the leg 13. This piston 15 has a duct 16 which communicates with a pressure medium source, not shown, for loading the rail 9 in the direction of the lateral surface of the mould parts 6.

The bottom piece 12 of each frame 11 carries a pair of guiding rollers 17 for contact against the lateral surfaces of the bed 5.

In FIG. 1, the center frame 11 is shown connected to a reciprocating mechanism comprising a fluid operated double-action cylinder 18, the piston rod 19 of which is, via a rocking arm 20, pivotably connected to the bottom piece 12 of the frame 11. By this means, it is possible to impart a forward and return movement to the two rails 9 along the guideway or bed 5. During the forward stroke of this movement pressure fluid is admitted to the jack 14, 15 so that the mould parts 6 are clamped between the two lateral rails 9. During the backward or return stroke, on the other hand, the fluid pressure is relieved, so that it is possible for the two rails 9 to slide back almost frictionless along the sides of the mould parts 6. As mentioned in the foregoing,

the reciprocating mechanism 18 may be adapted in such a way that, during the normal operation of the machine, the force of displacement exerted on the mould parts by the associated frame 11 and the two lateral rails 9 is, by itself, insufficient to start the displacement of the mould parts, which is only initiated when the pattern board 3, via the mould part 4 last completed, exerts a supplementary pressure on the mould 6.

It is indicated in FIG. 1 that the rails 9 may be composed of sections which are connected to each other in a suitable manner, e.g., by means of strap plates 21. It may, in such a case, be expedient to allow the rail section, which leads during the return stroke, that is to say the left-hand rail section in FIG. 1, to project very slightly inwards the mould parts relative to the other rail section. This projection need only be of the magnitude of one tenth of a millimeter and serves to eliminate the risk .of the sides of the mould parts being scraped off during the return stroke of the rails.

For the sake of completeness it should be noted that it is possible to employ other mould part advancing means than those comprising lateral rails 9. "By way of example, the guideway 5 may constitute a reciprocating or travelling grate consisting of alternating fixed and movable grate bars, of which the latter may be reciprocated in the longitudinal direction of the guideway and may be raised and lowered, so that during their forward stroke they keep the mould parts 6 raised ever so slightly clear of the stationary grate bars, while during their backward stroke the movable bars are lowered completely or partly clear of the underside of the mould parts.

What is claimed is:

1. In apparatus for successively producing identical casting cavity defining mould parts that are aligned in abutment for advancement to a casting station, comprising a mould part forming apparatus including a moulding chamber and at least one pattern board that is displaceable within said moulding chamber to first compress and form moulding material therein to produce a mould part defining a casting cavity and then to push the mould part thus produced from said chamber for addition to a casting mould consisting of a plurality of previously produced aligned mould parts, and

a substantially horizontally disposed guideway to successively receive the mould parts as they are produced and to support the mould parts in abutment during intermittent advancement, along said guideway concurrently with the ejection of a mould part from said chamber and advanced toward said casting station,

the improvement comprising reciprocating mould part advancing means movably mounted longitudinally of said guideway, said means including engaging means intermittently movable into and out of engagement with at least one exposed unsupported surface of a plurality of the aligned mould parts and, in the engaged position, being displaceable in the mould part advancing direction, said means also including power means for reciprocating said engaging means a distance substantially equal to the travel of said pattern board and at the same speed as that of said pattern board as it ejects a new mould part to assist in advancing said aligned mould parts along said guideway.

2. Apparatus according to claim 1, wherein said mould part advancing means engages the mould parts only with sufficient pressure to frictionally engage the mould parts to only assist in advancement of the mould parts by said pattern board, the pressure applied by said advancing means being insufficient to per se advance the mould parts.

3. Apparatus as claimed in claim 1, wherein said mould part advancing means comprise two rails located at opposite sides of the guideway and parallel thereto, said rails being supported by the guideway so as to be longitudinally displaceable, and being connected to a common reciprocating mechanism, at least one of the rails being transversely movable towards and away from the mould parts standing on. the guideway.

4. Apparatus as claimed in claim 1, wherein said mould part advancing means comprisea pair of rails extending along opposites side of said guideway and supported for longitudinal displacement therealong, said pair of rails being connected to each other by yoke-like frames extending below said guideway, at least one of said yoke-like frames being connected to a reciprocating mechanism, and at least one of said pair of rails being connected to said yoke-like frames by pneumatic jacks operative to bring the rails into and out of firm engagement with the lateral sides of the mould.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,744,552 Dated Julv 10, 1973 Invent-(5) Henning Borge Lundsgart It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Claim 1, line 26 delete "unsupported".

Signed and Scaled this Thirty-first Day of August m2 [SEALI Aunt:

GERALD .I. MOSSINGHOFF Anating Ojflcer Commissioner 6 f Parents and Trademarks 

1. In apparatus for successively producing identical casting cavity defining mould parts that are aligned in abutment for advancement to a casting station, comprising a mould part forming apparatus including a moulding chamber and at least one pattern board that is displaceable within said moulding chamber to first compress and form moulding material therein to produce a mould part defining a casting cavity and then to push the mould part thus produced from said chamber for addition to a casting mould consisting of a plurality of previously produced aligned mould parts, and a substantially horizontally disposed guideway to successively receive the mould parts as they are produced and to support the mould parts in abutment during intermittent advancement along said guideway concurrently with the ejection of a mould part from said chamber and advanced toward said casting station, the improvement comprising reciprocating mould part advancing means movably mounted longitudinally of said guideway, said means including engaging means intermittently movable into and out of engagement with at least one exposed unsupported surface of a plurality of the aligned mould parts and, in the engaged position, being displaceable in the mould part advancing direction, said means also including power means for reciprocating said engaging means a distance substantially equal to the travel of said pattern board and at the same speed as that of said pattern board as it ejects a new mould part to assist in advancing said aligned mould parts along said guideway.
 2. Apparatus according to claim 1, wherein said mould part advancing means engages the mould parts only with sufficient pressure to frictionally engage the mould parts to only assist in advancement of the mould parts by said pattern board, the pressure applied by said advancing means being insufficient to per se advance the mould parts.
 3. Apparatus as claimed in claim 1, wherein said mould part advancing means comprise two rails located at opposite sides of the guideway and parallel thereto, said rails being supported by the guideway so as to be longitudinally displaceable, and being connected to a common reciprocating mechanism, at least one of the rails being transversely movable towards and away from the mould parts standing on the guideway.
 4. Apparatus as claimed in claim 1, wherein said mould part advancing means comprise a pair of rails extending along opposites side of said guideway and supported for longitudinal displacement therealong, said pair of rails being connected to each other by yoke-like frames extending below said guideway, at least one of said yoke-like frames being connected to a reciprocating mechanism, and at least one of said pair of rails being connected to said yoke-like frames by pneumatic jacks operative to bring the rails into and out of firm engagement with the lateral sides of the mould. 